Who to bloch websites

who can i block any website in my computer just like google and youtube.
any body search these on my computer websites can not open.
Answer #1
I want to write website for help.
Thanks you.
Answer #2
Add 127.0.0.1 websitesname.com To your hosts file. You can even divert it to another ip address if you want.
Answer #3
use method stated by tg-3223
or
go to www.whois.net and find out ip address of site u want to block.
Now use peerblock to block this ip address.